This image shows the approximate size of the Mars Exploration Rover Opportunity in comparison to the impressive impact crater dubbed "Endurance," which is roughly 130 meters (430 feet) across. A model of Opportunity has been superimposed on top of an approximate true-color image taken by the rover's panoramic camera. Scientists are eager to explore Endurance for clues to the red planet's history. The crater's exposed walls provide a window to what lies beneath the surface of Mars and thus what geologic processes occurred there in the past. While recent studies of the smaller crater nicknamed "Eagle" revealed an evaporating body of salty water, that crater was not deep enough to indicate what came before the water. Endurance may be able to help answer this question, but the challenge is getting to the scientific targets: most of the crater's rocks are embedded in vertical cliffs. Rover planners are developing strategies to overcome this obstacle. This image is a portion of a larger mosaic taken with the panoramic camera's 480-, 530- and 750-nanometer filters on sols 97 and 98.